Wafer guides for processing semiconductor substrates

ABSTRACT

A wafer guide includes a horizontal support panel and at least three vertical panels attached on one surface of the support panel. Each of the vertical panels has a vertical body panel and a plurality of protrusions upwardly extended from a top surface of the vertical body panel. Gap regions between the protrusions act as slots for holding wafers. Sidewalls of the slots have a convex shaped profile when viewed from a top view, and bottom surfaces of the slots also have a convex shaped profile when viewed from a cross sectional view that crosses the vertical panels.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 11/234,033 filed on Sep. 24, 2005, the disclosure of which is hereinincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cleaning/drying apparatus and, moreparticularly, to wafer guides for holding semiconductor substrates.

2. Description of Related Art

A wet process, such as a wet cleaning process or a wet etching process,is frequently used in fabricating semiconductor devices. Semiconductorsubstrates, e.g., semiconductor wafers, are dipped into a chemicalsolution to perform the wet process. A portion of the chemical solutionmay remain on the semiconductor wafers even after finishing the wetprocess. The remaining chemical solution is removed by a rinse process.The rinse process is typically performed using de-ionized (DI) water.The DI water on the wafers is removed by a drying process.

A wafer guide holds the wafers during the wet processes, the rinseprocess, and the drying process. That is, the wafers are inserted intoslots of the wafer guide. As a result, the wafers are in contact withthe wafer guide. Accordingly, even though the drying process isperformed, the DI water around contact points between the wafer guideand the wafers may not be removed. The DI water remaining on the wafersafter the drying process generates surface defects called “water spots”.The water spots substantially reduce the yield of the semiconductordevices from the wafers. Therefore, there is a need to decrease thecontact areas between the wafers and the wafer guide.

The slots of the wafer guide have widths greater than the thickness ofthe wafers. The width of the slots prevent scratches from being formedon the surfaces of the wafers when the wafers are loaded into the slots.Each of the wafers loaded in the slots randomly inclines to one side andtherefore, spaces between the wafers are irregular. In particular, whenthe spaces between the front surfaces of the adjacent wafers arenon-uniform, the drying efficiency of the drying process issubstantially reduced.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, wafer guidesimprove the drying efficiency of a drying process for semiconductorwafers.

According to an embodiment of the present invention, wafer guides reducethe size of the contact areas between the semiconductor wafers and thewafer guides.

According to an embodiment of the present invention, wafer guidesuniformly control the spaces between the semiconductor wafers.

To achieve the features and other advantages of the present invention,wafer guides according to an embodiment of the present invention areused in a wet process and a drying process.

According to an embodiment of the present invention, the wafer guidecomprises a support panel and at least three vertical panels attached onone surface of the support panel. The vertical panels are parallel toeach other and perpendicular to the support panel. Each of the verticalpanels has a vertical body panel and a plurality of protrusionsextending upwardly from a top surface of the vertical body panel. Theprotrusions define a plurality of slots. Sidewalls of the slots haveconvex shapes when viewed from a top view, and a bottom surface of eachslot has a convex shape when viewed from a cross sectional view passingthrough the slot between the protrusions.

The at least three vertical panels may comprise a first vertical paneland a second vertical panel, which are attached on both edges of thesupport panel respectively, and a central panel located between thefirst and second vertical panels. It is preferable that the bottomsurfaces of the slots in the central panel have asymmetrical profileswith respect to the plane that passes through a central point of thecentral panel and is parallel to the central panel.

According to another embodiment of the invention, the wafer guideincludes a support panel and at least three vertical panels attached onone surface of the support panel. The vertical panels are parallel toeach other and perpendicular to the support panel. Each of the verticalpanels has a vertical body panel and a plurality of protrusionsextending upwardly from a top surface of the vertical body panel todefine a plurality of slots. The protrusions comprise a hydrophobicmaterial, and the body panels comprise a hydrophilic material.

Each of the bottom surfaces of the slots preferably has a recessedgroove to reduce a contact area between the bottom surface of the slotand a semiconductor wafer inserted into the slot. Further, it ispreferable that sidewalls of the slots have convex shapes when viewedfrom a top view.

According to still another embodiment of the invention, the wafer guideincludes a support panel and at least three vertical panels attached onone surface of the support panel. The vertical panels are parallel toeach other and perpendicular to the support panel. Each of the verticalpanels has a vertical body panel and a plurality of protrusionsextending upwardly from a top surface of the body panel to define aplurality of slots. The protrusions comprise a first set of protrusionsinterleaved with a second set of protrusions. Sidewalls of theprotrusions comprise vertical lower sidewalls defining lower widths ofthe slots and positive sloped upper sidewalls extended from the lowersidewalls. The lower sidewalls of the second set of protrusions arehigher or lower than the lower sidewalls of the first set ofprotrusions.

The lower sidewalls of the protrusions may have convex shapes whenviewed from a top view. Also, the bottom surface of each the slot mayhave a convex shape when viewed from cross sectional view that passesthrough the slot between the protrusions.

The at least three vertical panels may comprise a first vertical paneland a second vertical panel, which are attached on both edges of thesupport panel respectively, and a central panel located between thefirst and second vertical panels. In this case, it is preferable thatthe bottom surfaces of the slots in the central panel have asymmetricalprofiles with respect to the plane that passes through a central pointof the central panel and is parallel to the central panel.

According to still another embodiment of the present invention, thewafer guide includes a support panel and at least three vertical panelsattached on one surface of the support panel. The vertical panels areparallel to each other and perpendicular to the support panel. Each ofthe vertical panels has a vertical body panel and a plurality ofprotrusions extending upwardly from a top surface of the vertical bodypanel to define a plurality of slots. The protrusions comprise a firstset of protrusions interleaved with a second set of protrusions.Sidewalls of the protrusions comprise lower sidewalls defining lowerwidths of the slots and positive sloped upper sidewalls extended fromthe lower sidewalls. The lower sidewalls of the second set ofprotrusions have vertical profiles, and the lower sidewalls of the firstset of protrusions have positive slopes, which are steeper than theupper sidewalls.

The vertical lower sidewalls may have the same height as the slopedlower sidewalls. The vertical lower sidewalls and the sloped lowersidewalls may have convex shapes when viewed from a top view. A bottomsurface of each slot may have a convex shape when viewed from crosssectional view that passes through the slot between the protrusions.

Further, the at least three vertical panels may comprise a firstvertical panel and a second vertical panel, which are attached on bothedges of the support panel respectively, and a central panel locatedbetween the first and second vertical panels. In this case, it ispreferable that the bottom surfaces of the slots in the central panelhave asymmetrical profiles with respect to the plane that passes througha central point of the central panel and is parallel to the centralpanel.

According to still another embodiment of the invention, the wafer guideincludes a support panel and at least three vertical panels attached onone surface of the support panel. The vertical panels are parallel toeach other and perpendicular to the support panel. Each of the verticalpanels has a vertical body panel and a plurality of protrusionsextending upwardly from a top surface of the vertical body panel todefine a plurality of slots. The slots comprise a first set of slots anda second set of slots. When viewed from a cross sectional view which istaken along the plane that parallel to the vertical panels, the bottomsurfaces of the first set of slots have the opposite slope to the bottomsurfaces of the second set of slots.

Sidewalls of the protrusions may comprise vertical lower sidewallsdefining lower widths of the slots and positive sloped upper sidewallsextended from the vertical lower sidewalls. It is preferable that is thevertical lower sidewalls have convex shapes when viewed from a top view.The bottom surfaces of the slots may have convex shapes when viewed fromcross sectional views that pass through the slots between theprotrusions.

Further, the at least three vertical panels may comprise a firstvertical panel and a second vertical panel, which are attached on bothedges of the support panel respectively, and a central panel locatedbetween the first and second vertical panels. In this case, it ispreferable that the bottom surfaces of the slots in the central panelhave asymmetrical profiles with respect to the plane that passes througha central point of the central panel and is parallel to the centralpanel.

According to still another embodiment of the present invention, a waferguide comprises a main wafer guide for holding semiconductor wafers andan auxiliary wafer guide having a wider width than the main wafer guide.The auxiliary wafer guide includes an auxiliary supporter that is widerthan the main wafer guide and a pair of parallel wafer supporters thatare disposed on about both edges of the auxiliary supporter toadditionally hold the semiconductor wafers.

The auxiliary wafer guide is physically connected to the main waferguide. Thus, the auxiliary wafer guide is moved together with the mainwafer guide. Alternatively, the auxiliary wafer guide may be separatedfrom the main wafer guide.

Each of the wafer supporters is fixed by vertical bars, which areextended from both ends of the wafer supporter to be in contact with theauxiliary supporter. Therefore, a space is provided under the respectivewafer supporters. As a result, fluid, which is introduced into gapregions between the wafers along a horizontal direction, flows from theoutside of the auxiliary wafer guide through the space under therespective wafer supporters. The fluid uniformly flows about thesurfaces of the wafers due to the presence of the spaces under the wafersupporters.

Each wafer supporter comprises a horizontal body having a first sidewalland a second sidewall that face each other and a plurality ofprotrusions that protruded from one of the first and second sidewalls.Spaces between the protrusions define a plurality of lumbar regions,which are in contact with the edge regions of the wafers. Each wafersupporter has a streamline shape when viewed from a cross sectional viewthat crosses the wafer supporter. Accordingly, in the event that fluidis introduced along the horizontal direction, which is perpendicular tothe first and second sidewalls, whirlpool generation is suppressed.

Alternatively, each wafer supporter may comprise two sidebars andfront/rear bars that connect the ends of the sidebars with each other.One of the sidebars is bent with a zigzag shape to provide a pluralityof protrusions. Spaces between the protrusions define a plurality oflumbar regions, which are in contact with the edge regions of thewafers.

According to still another embodiment of the present invention, thewafer guide comprises a support panel and at least three vertical panelsattached on one surface of the support panel. The vertical panels areparallel to each other and perpendicular to the support panel. One ofthe vertical panels is a central panel that passes through a centralpoint of the support panel. Each of the vertical panels has a verticalbody panel and a plurality of protrusions extending upwardly from a topsurface of the vertical body panel. The protrusions define a pluralityof slots. A plurality of wafers are inserted into the slots. Analignment tool is installed at the central panel. The alignment tooladjusts actual widths of the slots so that the wafers inserted in theslots are separated from each other by a substantially uniform space.

It is preferable that lower sidewalls of the protrusions have a verticalprofile.

The alignment tool comprises a cylinder for providing a space in thecentral panel and a piston inserted in the cylinder. A first fluid inletconduit and a second fluid inlet conduit are connected to both ends ofthe cylinder respectively. Thus, in the event that fluid is injectedinto the first fluid inlet conduit, the piston moves toward the secondfluid inlet conduit. In the event that the fluid is injected into thesecond fluid inlet conduit, the piston moves toward the first fluidinlet conduit. A plurality of pads are physically connected to thepiston. Each of the pads protrudes from the one sidewall of therespective protrusions or is retracted into the respective protrusionsaccording to the movement of the piston. When the pads are protruded,the actual widths of the slots are reduced to squeeze the wafers, whichare inserted into the slots. Therefore, the wafers are heldsubstantially vertically. In the event that the protrusions have uniformpitches, the spaces between the wafers are substantially uniform.

Alternatively, the alignment tool may comprise a first rotational axisand a second rotational axis, which are installed at both sides of thecentral panel respectively. The rotational axes are installed to beparallel with a straight line that penetrates the protrusions of thecentral panel. The first rotational axis penetrates a first group ofrollers. Similarly, the second rotational axis penetrates a second groupof rollers. The first and second groups of rollers have the same pitchas the protrusions of the central panel. The first rollers and one ofthe second rollers are located at both sides of each of the protrusionsrespectively. The first rollers rotate with the first rotational axis,and the second rollers rotate with the second rotational axis. Each ofthe rollers includes a first edge region having a first thickness and asecond edge region having a second thickness, which is greater than thefirst thickness. Thus, at least one of both sidewalls of the respectiverollers has a sloped profile.

When the wafers are loaded or unloaded, the first and second rotationalaxes are rotated so that all of the first edge regions of the rollersare arrayed downward. In this case, the wafers inserted in the slots arenot in contact with any of the rollers. However, if the first and secondrotational axes are rotated so that all of the second edge regions ofthe rollers are arrayed upward, front surfaces or backside surfaces ofthe wafers in the slots are in contact with the second edge regions. Asa result, the wafers are squeezed and held substantially vertically.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will be morereadily understood from the following detailed description of specificembodiments thereof when read in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a perspective view illustrating a wafer guide according to anembodiment of the present invention;

FIG. 2 is a top view illustrating a portion of a vertical panel of thewafer guide shown in FIG. 1;

FIG. 3 is a cross sectional view taken along the line I-I′ of FIG. 2;

FIG. 4 is a cross sectional view taken along the line II-II′ of FIG. 2;

FIG. 5 is another cross sectional view taken along the line II-II′ ofFIG. 2;

FIG. 6 is a side cross sectional view illustrating a portion of verticalpanels of the wafer guide according to an embodiment of the presentinvention;

FIG. 7 is a side cross sectional view illustrating a portion of verticalpanels of the wafer guide according to an embodiment of the presentinvention;

FIG. 8 is a side cross sectional view illustrating a portion of verticalpanels of the wafer guide according to an embodiment of the presentinvention;

FIG. 9 is a side cross sectional view illustrating a portion of verticalpanels of the wafer guide according to an embodiment of the presentinvention;

FIG. 10 is a front cross sectional view illustrating the wafer guideaccording to an embodiment of the present invention;

FIGS. 11 to 15 are schematic views for illustrating a method of cleaningand/or drying semiconductor wafers using the wafer guide shown in FIG.10 according to an embodiment of the present invention;

FIG. 16 is a perspective view illustrating a vertical panel unit of thewafer guide according to an embodiment of the present invention;

FIG. 17 is a cross sectional view of the vertical panel unit taken alongthe y-z plane of FIG. 16;

FIG. 18 is a perspective view illustrating a portion of vertical panelunits of the wafer guide according to an embodiment of the presentinvention;

FIG. 19 is a side view for illustrating a method of loading wafers intothe slots of FIG. 18 or unloading the wafers from the slots according toan embodiment of the present invention;

FIG. 20 is a side view for illustrating a method of arranging the wafersin the slots according to an embodiment of the present invention;

FIG. 21 is a perspective view of the wafer guide according to anembodiment of the present invention;

FIG. 22 is a front cross sectional view of the wafer guide shown in FIG.21;

FIG. 23 is a top view illustrating an embodiment of the auxiliary waferguide shown in FIG. 21; and

FIG. 24 is a front view illustrating an embodiment of the wafer guideshown in FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, the dimensions of elements are exaggerated for clarity. Likenumbers refer to like elements throughout the specification.

FIG. 1 is a perspective view illustrating a wafer guide according to anembodiment of the present invention.

Referring to FIG. 1, the wafer guide 10 comprises a support panel 1, afirst vertical panel 6 a and a second vertical panel 6 b located on bothedges of the support panel 1 respectively, and a central panel 6 clocated between the first vertical panel 6 a and the second verticalpanel 6 b. The central panel 6 c is disposed on a central region of thesupport panel 1 and is parallel with the first vertical panel 6 a andthe second vertical panel 6 b. The first vertical panel 6 a comprises afirst body panel 3 a and a plurality of first protrusions 5 a upwardlyextended from a top surface of the first body panel 3 a. The firstprotrusions 5 a define a plurality of first slots 7 a that correspond tothe gap regions between the first protrusions 5 a. Similarly, the secondvertical panel 6 b comprises a second body panel 3 b and a plurality ofsecond protrusions 5 b upwardly extended from a top surface of thesecond body panel 3 b. The second protrusions 5 b define a plurality ofsecond slots 7 b that correspond to the gap regions between the secondprotrusions 5 b. In addition, the central panel 6 c includes a centralbody panel 3 c and a plurality of central protrusions 5 c upwardlyextended from a top surface of the central body panel 3 c. The gapregions between the central protrusions 5 c correspond to central slots7 c. A plurality of wafers are inserted into the slots 7 a, 7 b and 7 c.The central slots 7 c are located at a lower level than the first slots7 a and the second slots 7 b. The level difference between the firstslots 7 a and the second slots 7 b and the central slots 7 c correspondto a diameter of the wafers.

A pitch size of the slots 7 a, 7 b and 7 c is reduced to increase abatch size of the wafers, which are treated during a single rinse/dryprocess. For example, in the event that the pitch size of the slots 7 a,7 b and 7 c is reduced from 10 mm to 5 mm, the number of wafers that canbe loaded into the wafer guide doubles. In addition, throughputincreases as the diameter of the wafers increases. Wafers having adiameter of 300 mm have been widely used as an alternative to wafershaving a diameter of 200 mm. As wafer size increases, the probabilitythat upper regions of adjacent wafers will contact each other due to thereduction of the pitch of the slots increases. Thus, the space betweenthe first vertical panel 6 a and the second vertical panel 6 b ispreferably increased from P1 to P2 as shown in FIG. 24, therebypreventing the wafers from coming into contact with each other. It ispreferable that the width of the support panel 1 corresponds to thediameter of the wafer. The heights of the first slots 6 a and secondslots 6 b are increased as the width of the support panel 1 increases inorder that bottom surfaces of the central slots 7 c as well as bottomsurfaces of the first slots 7 a and the second slots 7 b are in uniformcontact with the wafers inserted into the slots 7 a, 7 b and 7 c. Forexample, when the pitch of the slots is 7 mm and the diameter of thewafers is 300 mm, it is preferable that the level difference (Q of FIG.24) between the first slots 7 a and the second slots 7 b and the centralslots 7 c is at least 57 mm.

FIG. 2 is a top view illustrating a portion of the first vertical panel6 a, the second vertical panel 6 b or the central panel 6 c.

Referring to FIG. 2, sidewalls 5 s of the protrusions 5 a, 5 b and 5 chave a convex shape when viewed from a top view that is taken along thex-y plane of FIG. 1. Thus, in the event that the wafers are loaded intothe slots (e.g., 7 a, 7 b and 7 c of FIG. 1) between the protrusions 5a, 5 b and 5 c, it is possible to reduce contact areas between thewafers and the sidewalls 5 s.

FIG. 3 is a side sectional view taken along the line I-I′ of FIG. 2.

Referring to FIG. 3, top surfaces of the protrusions 5 a, 5 b and 5 care convex-shaped when viewed from a cross sectional view that isparallel to the y-z plane of FIG. 1. Accordingly, when the wafers areloaded onto the wafer guide (10 of FIG. 1), the wafers are inserted inthe slots 7 a, 7 b and 7 c.

FIG. 4 is a front sectional view taken along the line II-II′ of FIG. 2.

Referring to FIG. 4, bottom surfaces of the slots 7 a, 7 b and 7 c havea convex shape when viewed from a cross sectional view that is parallelto the x-z plane of FIG. 1. Therefore, each of the bottom surfaces ofthe slots 7 a, 7 b and 7 c is in contact with a tangent line parallel tothe x-axis of FIG. 1 at a single contact point 11. As a result, eachbottom surface is divided into a first bottom surface 3 s′ and a secondbottom surface 3 s″, which are located at both sides of the contactpoint 11 respectively. The first bottom surface 3 s′ and the secondbottom surface 3 s″ have a symmetrical profile to each other withrespect to the plane that is parallel to the y-z plane of FIG. 1 andpasses through the contact point 11. A first angle θ1 between the firstbottom surface 3 s′ and the tangent line is substantially identical to asecond angle θ2 between the second bottom surface 3 s″ and the tangentline.

The bottom surfaces of the slots 7 a, 7 b and 7 c may have asymmetricalsurface profiles. It is preferable that the bottom surfaces of thecentral slots 7 c have asymmetrical profiles as shown in FIG. 5.

Referring to FIG. 5, each bottom surface of the central slots 7 c is incontact with a semiconductor wafer 9 at the contact point 11. Thus, eachbottom surface is divided into a first bottom surface 3 t′ and a secondbottom surface 3 t″, which are located at both sides of the contactpoint 11 respectively. Here, a slope, or a curvature, of the firstbottom surface 3 t′ is different from a slope of the second bottomsurface 3 t″. For example, a first angle α between the wafer 9 and thefirst bottom surface 3 t′ is less than a second angle β between thewafer 9 and the second bottom surface 3 t″ as shown in FIG. 5. Duringthe drying process for removing de-ionized water on the wafer 9, thede-ionized water existing between the second bottom surface 3 t″ and thewafer 9 is substantially removed. This is because a surface tension ofthe de-ionized water between the second bottom surface 3 t″ and thewafer 9 is less than a surface tension of the de-ionized water betweenthe first bottom surface 3 t′ and the wafer 9. The surface tensiondifference is due to the difference between a first angle α and a secondangle β. As a result, it is possible to improve the drying efficiency ofthe wafer 9. Alternatively, the first angle α may be greater than thesecond angle β.

FIG. 6 is a cross sectional view illustrating vertical panels of thewafer guide according to an embodiment of the invention. FIG. 6 is thecross sectional view taken along the plane that is parallel to the y-zplane of FIG. 1.

Referring to FIG. 6, each of the vertical panels of the wafer guidecomprises vertical body panel 3 and a plurality of protrusions 5attached on the top surface of the body panel 3. The gap regions betweenthe protrusions 5 act as slots 7 in which wafers are inserted. The bodypanel 3 comprises a hydrophilic material, and the protrusions 5 comprisea hydrophobic material. For example, the body panel 3 may comprisequartz, and the protrusions 5 may comprise a fluorine system polymer.Thus, the de-ionized water existing between the wafers in the slots 7and the protrusions 5 flows down toward the body panel 3. As a result,the drying efficiency is improved.

In addition, each of the bottom surfaces of the slots 7 preferably has arecessed groove 21. In this case, contact areas between the wafers andbottom surfaces of the slots 7 can be reduced because of the presence ofthe groove 21. Accordingly, the drying efficiency can be improved.

Further, sidewalls of the protrusions 5 (e.g., sidewalls of the slots 7)may have convex shape when viewed from a top view. Therefore, it ispossible to reduce the size of the contact areas between the wafers inthe slots 7 and the sidewalls of the protrusions 5. Thus, the dryingefficiency can be improved.

FIG. 7 is a cross sectional view illustrating vertical panels of thewafer guide according to an embodiment of the present invention. FIG. 7is the cross sectional view taken along the plane that is parallel tothe y-z plane of FIG. 1.

Referring to FIG. 7, each of the vertical panels comprises a verticalbody panel 31 and a plurality of protrusions extended from a top surfaceof the body panel 31. The protrusions include a second set ofprotrusions 33 a interleaved with a first set of protrusions 33 b. Gapregions between the protrusions correspond to slots 35. Sidewalls of theprotrusions include vertical lower sidewalls and positive sloped uppersidewalls. The vertical lower sidewalls define lower widths of the slots35. Upper widths of the slots 35 are wider than the lower widthsthereof. This is due to the positive sloped upper sidewalls.

A second set of protrusions 33 a comprise first lower sidewalls 33 s′,and a first set of protrusions 33 b comprise second lower sidewalls 33s″. The height H1 of the first lower sidewalls 33 s′ is greater than theheight H2 of the second lower sidewalls 33 s″. Thus, the wafers in theslots 35 may be inclined toward the first set of protrusions 33 b. Afirst group of wafers 37 a inserted in a second set of slots areinclined toward a right side as shown in FIG. 7. A second group ofwafers 37 b inserted in a first set of slots are inclined toward a leftside as shown in FIG. 7. As a result, a space between the wafers 37 aand 37 b located at both sides of the respective second set ofprotrusions 33 a becomes wider away from the vertical body panel 31. Aspace between the wafers 37 a and 37 b located at both sides of therespective first set of protrusions 33 b becomes narrower away from thevertical body panel 31. Therefore, if the wafers are loaded so thatfront surfaces of the pair of wafers 37 a and 37 b located in both slotsof the second set of protrusion 33 a face to each other, the spacesbetween the front surfaces of the wafers are relatively wider than thosebetween the backside surfaces of the wafers. Thus, fluid can be readilyintroduced into the gap regions between the front surfaces of the wafersduring a rinsing or a drying process of the wafers. As a result, it ispossible to improve a rinsing efficiency or a drying efficiency to thefront surfaces of the wafers.

At least the lower sidewalls 33 s′ and 33 s″ may have a convex shapewhen viewed from a top view, for example, as shown in FIGS. 2 and 3.Also, bottom surfaces of the slots 35 may have a convex shape as shownin FIG. 4. In this case, it is possible to minimize the contact areasbetween wafers 37 a and 37 b and the vertical panels. Further, thebottom surfaces of the slots 35 may have an asymmetrical profile asexplained with reference to FIG. 5.

FIG. 8 is a cross sectional view illustrating vertical panels of thewafer guide according to an embodiment of the present invention.

Referring to FIG. 8, each of the vertical panels comprises a verticalbody panel 41 and a plurality of protrusions extended from the topsurface of the body panel 41. The protrusions include a second set ofprotrusions 43 a interleaved with a first set of protrusions 43 b. Gapregions between the protrusions correspond to slots 45. Sidewalls of theprotrusions include lower sidewalls and positive sloped upper sidewalls.The lower sidewalls define lower widths of the slots 45. Upper widths ofthe slots 45 are wider than the lower widths thereof. This is due to thepositive sloped upper sidewalls.

Lower sidewalls of the second set of protrusions 43 a, e.g., a firstlower sidewalls 43 s′, have a vertical profile, and lower sidewalls ofthe first set of protrusions 43 b, e.g., a second lower sidewalls 43 s″,have a positive sloped profile. The second lower sidewalls 43 s″ have asteeper slope than the upper sidewalls. As a result, wafers 47 a and 47b in the slots 45 may be inclined toward the a first set of protrusions43 b. Thus, it is possible to improve a rinsing efficiency or a dryingefficiency to the front surfaces of the wafers.

Further, the lower sidewalls 43 s′ and 43 s″ may have a convex shapewhen viewed from a top view, for example, as shown in FIGS. 2 and 3.Also, the bottom surfaces of the slots 45 may have a surface profile asshown in FIGS. 4 and 5.

FIG. 9 is a cross sectional view illustrating vertical panels of thewafer guide according to an embodiment of the present invention.

Referring to FIG. 9, each of the vertical panels comprises a verticalbody panel 51 and a plurality of protrusions extended from a top surfaceof the body panel 51. Gap regions between the protrusions correspond toslots 55. The protrusions include a second set of protrusions 53 ainterleaved with a first set of protrusions 53 b. Similarly, the slots55 include a second set of slots interleaved with a first set of slots.Sidewalls of the slots 55, e.g., sidewalls of the protrusions, havevertical lower sidewalls and positive sloped upper sidewalls. Bottomsurfaces 55 a of the second set of slots have an opposite slope to thebottom surfaces 55 b of the first set of slots when viewed from a crosssectional view taken along a plane that is parallel to the verticalpanels. Portions where a second set of bottom surfaces 55 a are incontact with the sidewalls of the second set of protrusions 53 a arehigher than portions where a second set of bottom surfaces 55 a are incontact with the sidewalls of the first set of protrusions 53 b. Thus, asecond set of wafers 57 a inserted in the second set of slots areinclined toward the first set of protrusions 53 b as shown in FIG. 9.Also, portions where a first set of bottom surfaces 55 b are in contactwith the sidewalls of the second set of protrusions 53 a are higher thanportions where the first set of bottom surfaces 55 b are in contact withthe sidewalls of the first set of protrusions 53 b. Thus, a first set ofwafers 57 b inserted in the first set of slots are inclined toward thefirst set of protrusions 53 b as shown in FIG. 9. Accordingly, it ispossible to improve a rinsing efficiency or a drying efficiency to thefront surfaces of the wafers.

Furthermore, the vertical lower sidewalls may have a convex shape whenviewed from a top view, for example, as shown in FIGS. 2 and 3. Thebottom surfaces 55 a and 55 b also may have a surface profile as shownin FIGS. 4 and 5.

FIG. 10 is a schematic front cross sectional view illustrating a waferguide according to an embodiment of the present invention.

Referring to FIG. 10, a wafer guide comprises a main wafer guide 10having a first width W1 and an auxiliary wafer guide 61 having a secondwidth W2 that is wider than the first width W1. The main wafer guide 10may have the same configuration as the wafer guides described withreference to FIGS. 1 to 6. The auxiliary wafer guide 61 includes anauxiliary support portion having the second width W2 and a pair ofparallel wafer supporters located on both edges of the auxiliary supportportion to additionally hold wafers 63 loaded on the main wafer guide10.

A space between the pair of wafer supporters is wider than the width ofthe main wafer guide 10. Thus, it is possible to maintain substantiallyuniform spaces between the wafers 63 loaded on the main wafer guide 10.

The auxiliary wafer guide 61 may be simultaneously moved with is themain wafer guide 10. The auxiliary wafer guide 61 may be movedindependently of the main wafer guide 10.

FIGS. 11 to 15 are schematic views for illustrating a method of usingthe wafer guide shown in FIG. 10.

Referring to FIG. 11, a chamber 73 is located on a wet bath 71 thatstores liquid 75 such as a chemical solution or de-ionized water. Abottom of the chamber 73 is open. Thus, the chamber 73 is connected tothe wet bath 71. The wafer guide shown in FIG. 10 is located in thechamber 73. A plurality of wafers 63 are loaded on the wafer guide. Inthis case, the wafers 63 are supported by the auxiliary wafer guide 61as well as the main wafer guide 10. Thus, upper portions of the wafers63 as well as lower portions thereof are separated from each other by asubstantially uniform distance.

Referring to FIG. 12, the wafer guide descends downward, thereby dippingthe wafers 63 into the liquid 75. In the event that the liquid 75 is acleaning solution, such as a chemical solution, the wafers 63 arecleaned. Alternatively, in the event that the liquid 75 is de-ionizedwater (DI water), the wafers 63 are rinsed. The cleaning process and therinse process may be repeatedly performed in the wet bath 71.

Referring to FIG. 13, a drying gas is introduced into the chamber 73after completing the rinse process. The wafer guide is lifted up toexpose upper portions 63 a of the wafers 63. The auxiliary wafer guide61 is not exposed to the air over the DI water 75, during introductionof the dry gas. Spaces between the exposed upper portions 63 a maintaina substantially uniform distance due to the auxiliary wafer guide 61.The DI water existing on the exposed upper portions 63 a can beefficiently removed.

Referring to FIG. 14, the main wafer guide 10 is lifted up to completelyexpose lower portions 63 b of the wafers 63 after drying the upperportions 63 a of the wafers. While free of the auxiliary wafer guide 61,the wafers 63 may lean. However, the spaces between the lower portions63 b of the wafers may maintain a substantially uniform distance due tothe main wafer guide 10, even though the wafers 63 are inclined. Thus,the DI water existing on the exposed lower portions 63 b is alsoefficiently removed.

Referring to FIG. 15, the DI water 75 in the wet bath 71 is drained.Accordingly, the auxiliary wafer guide 61 is exposed, and the drying gasintroduced into the chamber 73 dries the exposed auxiliary wafer guide61.

-   -   The auxiliary wafer guide 61 may be lifted up to additionally        support the wafers 63. A purge gas, such as a nitrogen gas, may        be additionally introduced into the chamber 73.

FIG. 21 is a perspective view for illustrating a wafer guide having afixed auxiliary wafer guide.

Referring to FIG. 21, a first wafer supporter 132 a and a second wafersupporter 132 b are located on both edges of a support panel 121respectively. The support panel 121 is parallel with an x-y plane. Thefirst wafer supporter 132 a and the second wafer supporter 132 b aredisposed to be parallel with a y-axis. The support panel 121 isconnected to a pair of first vertical bars 135 a extended from both endsof the first wafer supporter 132 a. The first wafer supporter 132 a isfixed to the support panel 121 by the first vertical bars 135 a.Similarly, the second wafer supporter 132 b is fixed to the supportpanel 121 by a pair of second vertical bars 135 b. The first wafersupporter 132 a comprises a first horizontal body 129 a having a pair ofparallel sidewalls and a plurality of first protrusions 131 a protrudedfrom one of the parallel sidewalls. The first protrusions 131 a define aplurality of first lumbar regions 133 a. The second wafer supporter 132b comprises a second horizontal body 129 b having a pair of parallelsidewalls and a plurality of second protrusions 131 b protruded from oneof the parallel sidewalls. The second protrusions 131 b define aplurality of second lumbar regions 133 b. The first lumbar regions 133 aand the second lumbar regions 133 b act as auxiliary slots holding aplurality of wafers.

Three vertical panels, which are parallel with the y-axis, are attachedon the support panel 121 between the first wafer supporter 132 a and thesecond wafer supporter 132 b. The vertical panels comprise a centralpanel 126 c passing through a central portion of the support panel 121,a first vertical panel 126 a located between the central panel 126 c andthe first wafer supporter 132 a, and a second vertical panel 126 blocated between the central panel 126 c and the second wafer supporter132 b. The central panel 126 c as well as the first vertical panel 126 aand the second vertical panel 126 b may have a configuration as shown inFIGS. 1 to 5. That is, the first vertical panel 126 a comprises a firstvertical body panel 123 a and a plurality of first protrusions 125 aextended from a top surface of the first vertical body panel 123 a. Thefirst protrusions 125 a define a plurality of first slots 127 a.Similarly, the second vertical panel 126 b comprises a second verticalbody panel 123 b and a plurality of second protrusions 125 b extendedfrom a top surface of the second vertical body panel 123 b. The secondprotrusions 125 b define a plurality of second slots 127 b. Also, thecentral panel 126 c comprises a central body panel 123 c and a pluralityof central protrusions 125 c extended from a top surface of the centralbody panel 123 c. The central protrusions 125 c define a plurality ofcentral slots 127 c.

The central panel 126 c as well as the first vertical panel 126 a andthe second vertical panel 126 b may be supported by another supportpanel (not shown) separated from the support panel 121. In this case,the first vertical panel 126 a and the second vertical panel 126 b, thecentral panel 126 c, and the other support panel comprise the main waferguide 10 of FIG. 10. The first wafer supporter 132 a and the secondwafer supporter 132 b, the first vertical bar 135 a and the secondvertical bar 135 b, and the support panel 121 comprise the auxiliarywafer guide 61 of FIG. 10.

FIG. 22 is a front view illustrating the wafer guide of FIG. 21 as wellas wafers loaded on the wafer guide.

Referring to FIG. 22, the first wafer supporter 132 a and the secondwafer supporter 132 b additionally hold edges of wafers 137 loaded onthe main wafer guide, thereby keeping the spaces between the wafers 137substantially uniform. The main wafer guide may comprise the supportpanel 121 and the first vertical panel 126 a and the second verticalpanel 126 b.

The first wafer supporter 132 a and the second wafer supporter 132 bhave a streamlined shape when viewed from a cross sectional view that isparallel with the x-z plane of FIG. 21. Accordingly, it allows a dryinggas, which is supplied into regions between the wafers 137 along thex-axis direction of FIG. 21, to smoothly flow without forming awhirlpool.

FIG. 23 is a top view illustrating an embodiment of the first wafersupporter 132 a or the second wafer supporter 132 b shown in FIG. 21.

Referring to FIG. 23, a wafer supporter 140 a comprises a pair of sidebars 141 and 147, a front bar 149 connecting front ends of the side bars141 and 147 with each other, and a rear bar (not shown) connecting rearends of the side bars 141 and 147 with each other. One of the side bars141 and 147 (for example, 147 of FIG. 23) has a bent shape. Thus, thebent side bar 147 has a plurality of protrusions 143 that define aplurality of lumbar regions 145. The lumbar regions 145 hold edges ofthe wafers 137 shown in FIG. 22. As a result, the side bars 141 and 147,the front bar 149 and the rear bar comprise a closed loop that surroundsa space 151.

FIG. 16 is a perspective view illustrating a vertical panel unit of awafer guide according to an embodiment of the present invention, andFIG. 17 is a cross sectional view of the vertical panel unit taken alonga y-z plane of FIG. 16.

Referring to FIGS. 16 and 17, the vertical panel unit 80 may beinstalled instead of the central panel 6 c shown in FIG. 1. In addition,the vertical panel unit 80 may be installed instead of the firstvertical panel 6 a and the second vertical panel 6 b shown in FIG. 1.The vertical panel unit 80 comprises a vertical body panel 81 and aplurality of protrusions 83 extended from a top surface of the bodypanel 81. The body panel 81 is parallel with a y-z plane, and theprotrusions 83 are arrayed in a line along a y-axis. Gap regions 85between the protrusions 83 serve as slots in which wafers 99 areinserted. Preferably, lower sidewalls of the protrusions 83, e.g., lowersidewalls of the slots 85, have a vertical profile.

A cylinder 87, which is parallel with the y-axis, is provided in thebody panel 81. A piston 89 is disposed in the cylinder 87. The ends ofthe cylinder 87 are connected to a first fluid inlet conduit 95 and asecond fluid inlet conduit 97 respectively. Thus, in the event thatfluid such as a liquid or a gas is injected into the cylinder 87 throughthe first fluid inlet conduit 95, the piston 89 moves toward a direction“B”, e.g., toward the second fluid inlet conduit 97. Alternatively, inthe event that the fluid is injected into the cylinder 87 through thesecond fluid inlet conduit 97, the piston 89 moves toward a direction“A”, e.g., toward the first fluid inlet conduit 95.

A plurality of pad cylinders 91 are provided inside the protrusions 83.A pad 93 is disposed in each of the pad cylinders 91 respectively. Thepads 93 are physically connected to the piston 89 to simultaneously movewith the piston 89. Accordingly, in the event that the fluid is injectedthrough the second fluid inlet conduit 97, the piston 89 moves towardthe first fluid inlet conduit 95 and each pad 93 is protruded from arespective sidewall of the protrusions 83. As a result, the wafers 99loaded in the slots 85 are squeezed and held vertically. Therefore, thespaces between the wafers 99 have a substantially uniform distance.

An operation for loading the wafers 99 on the vertical panel unit 80 orfor unloading the wafers 99 from the vertical panel unit 80 is achievedafter introducing the fluid into the first fluid inlet conduit 95 tomove the pads 93 inward, e.g., into the sidewalls of the protrusions 83.

The cylinder 87, the piston 89, the first fluid inlet conduit 95 and thesecond fluid inlet conduit 97, the pad cylinders 91 and the pads 93comprise a wafer alignment tool.

FIG. 18 is a perspective view illustrating an embodiment of the verticalpanel unit shown in FIG. 17. FIG. 19 is a side view illustrating amethod of loading or unloading wafers using the vertical panel unitshown in FIG. 18, and FIG. 20 is a side view for illustrating a methodof aligning wafers using the vertical panel unit shown in FIG. 18. FIGS.19 and 20 are side views shown toward a direction “S” indicated in FIG.18.

Referring to FIGS. 18, 19 and 20, the vertical panel unit 100 may beinstalled instead of the central panel 6 c shown in FIG. 1. In addition,the vertical panel unit 100 may also be installed instead of the firstvertical panel 6 a and the second vertical panel 6 b shown in FIG. 1.The vertical panel unit 100 comprises a vertical body panel 101 and aplurality of protrusions 103 extended from a surface of the body panel101. The body panel 101 is parallel with a y-z plane of FIG. 18, theprotrusions 103 are arrayed in a line along the y-axis. Gap regions 105between the protrusions 103 correspond to slots in which wafers 111 areinserted. It is preferable that lower sidewalls of the protrusions 103,e.g., lower sidewalls of the slots 105, have a vertical profile. Thebody panel 101 and the protrusions 103 comprise a vertical panel.

A first rotational axis 107 a and a second rotational axis 107 b areinstalled at both sides of the vertical panel respectively. The firstrotational axis 107 a penetrates central portions of a first group ofrollers 109 a, and the second rotational axis 107 b penetrates centralportions of a second group of rollers 109 b. The first group of rollers109 a and the second groups of rollers 109 b are located at both sidesof the protrusions 103 respectively. The rollers 109 a and 109 b arearrayed to have the same pitch as the protrusions 103. Also, the rollers109 a and 109 b are fixed to the rotational axes 107 a and 107 b,thereby simultaneously rotating with the rotational axes 107 a and 107b. The rotational axes 107 a and 107 b and the rollers 109 a and 109 bcomprise a wafer alignment tool.

Each of the rollers 109 a and 109 b includes a first edge having a firstthickness D1 and a second edge having a second thickness D2 that isgreater than the first thickness D1. Accordingly, each of the rollers109 a and 109 b has at least one sloped sidewall. First sidewalls SW1 ofthe rollers have a vertical profile, and second sidewalls SW2 oppositethe first sidewalls SW1 have a sloped profile. That is to say, normallines to the first sidewalls SW1 are parallel with the rotational axes109 a and 109 b, and normal lines to the second sidewalls SW2 have apredetermined angle with respect to the rotational axes 109 a and 109 b.Thus, in the event that the first and second rotational axes 107 a and107 b are rotated so that the first edges are upwardly arrayed as shownin FIG. 19, it allows the wafers 1111 to be loaded or unloaded. In theevent that the first and second rotational axes 107 a and 107 b arerotated so that the second edges are upwardly arrayed as shown in FIG.20, actual widths of the slots 105 are reduced due to the second edges.Therefore, the wafers 1111 in the slots 105 are squeezed and heldsubstantially vertically. As a result, spaces between the wafers 111have a substantially uniform distance.

Although not shown in the figures, all of the first and second sidewallsSW1 and SW2 may have sloped profiles.

As described above, according to the present invention, it is possibleto reduce contact areas between the wafer guide and the wafers. Thus, adrying efficiency can be improved. In addition, distances between thewafers can be uniformly adjusted using the auxiliary wafer guide or thewafer alignment tool. Therefore, the drying efficiency can be improved.

1. A wafer guide comprising: a support panel; and at least threevertical panels attached on one surface of the support panel, whereineach of the vertical panels has a vertical body panel and a plurality ofprotrusions extended from a top surface of the vertical body panel todefine a plurality of slots, each of the plurality of slots having abottom surface that exhibits a convex shape when viewed from a crosssectional view that crosses the body panel.
 2. The wafer guide of claim1, wherein the vertical panels comprise a first vertical panel and asecond vertical panel attached on both edges of the support panelrespectively and a central panel located between the first and secondvertical panels.
 3. The wafer guide of claim 2, wherein each of thebottom surfaces of the plurality of slots in the central panel has anasymmetrical profile with respect to a plane that is parallel with thecentral panel and passes through a central portion of the central panel.4. The wafer guide of claim 2, wherein a level difference between theslots of the first vertical panel and the second vertical panel and theslots of the central panel is at least 57 mm.
 5. The wafer guide ofclaim 1, wherein each of the plurality of slots further has a sidewallthat exhibits a convex shape when viewed from a top view.
 6. The waferguide of claim 1, wherein the plurality of protrusions comprising ahydrophobic material and the vertical body panel comprising ahydrophilic material.
 7. The wafer guide of claim 6, wherein thehydrophobic material is fluorine system polymer, and the hydrophilicmaterial is quartz.